Could a superearth be hospitable (survivable?) for humans?

[chill_factor]

i think it would be almost unsurvivable except by a few sorts of athletes, astronauts and other highly conditioned and trained people.

your veins would struggle to return blood to your heart. that's a big problem.

http://en.wikipedia.org/wiki/Venous_return

if you fell down from what's a minor step, it would be very serious.

also, your spinal cord does not appreciably increase in strength regardless of how much exercise you get or how much you eat. but the spinal cord is the only thing supporting your head.

finally, adaptability is not symmetric. humans can survive body temperature - 50 degrees for hours. you'll get toasted at body temperature + 50 degrees, within minutes. adapting to 0 g is much much much easier than adapting to 2 g.

this is just the gravity aspect.

 

[mfb]

you'll get toasted at body temperature + 50 degrees, within minutes.

Saunas are not deadly within minutes (usually), but the asymmetry is there, of course.

There are centrifuges where it would be possible to test the influence of 2g for more than several minutes (=typical timescale of a rocket launch), but I don't know of long-term tests there.

 

[Damo ET]

Well, 'we' would probably have to go down the path of an exoskeleton (partial at least) when moving around on the planet itself, to counter all of the effects of the extra gravity. Seems like it would be better overall option.
But what about the plants? Has anyone experimented growing things in a higher gravity state?


Damo

 

[Drakkith]

Well, 'we' would probably have to go down the path of an exoskeleton (partial at least) when moving around on the planet itself, to counter all of the effects of the extra gravity. Seems like it would be better overall option.
But what about the plants? Has anyone experimented growing things in a higher gravity state?


Damo

An exoskeleton, while nice to have if you have to move things around, doesn't help the internal stresses the body would face.

 

[SW VandeCarr]

I don't know your requirements for a habitable super-earth, but if you're willing to accept the smaller gas giants beyond Jupiter, they all have near earth gravity and not too far below the gas "surface" there's liquid water and earth like temperatures (at least for Saturn). One could conceivably have floating colonies there.

In the extreme, the planet could be "wrapped" creating a huge surface area heated from below, with 1 g gravity and an atmosphere created from venting a selected proportion of gases from the interior. Since we are in the area of semi-plausible sci-fi, the wrapping could be accomplished by microorganisms adapted to a particular atmospheric level, using CO2 and methane as a carbon source and whose product forms dense floating webs that eventually interconnect.

www.esa.int/esaMI/Cassini-Huygens/SEMPQ6HHZTD_0.html

 

[ImaLooser]

You know, I've never really thought much about immunity vs local organisms. I suppose its possible, if not probable, for either ourselves to be completely immune to practically everything on the planets, or extremely vulnerable to said organisms?

If you can't digest it, it can't digest you.

Basic rule of space exploration.

 

[mfb]

If you can't digest it, it can't digest you.

Basic rule of space exploration.

Please provide a source (or at least a good reason) for that claim.

Here are counterexamples to take into account:
We can digest plants, but how can plants digest us?
Viruses can digest us, but how can we digest viruses?